Cov pa roj carbon ruaj khov siab thiab cov sulfur tsawg, nitrogen tsawg thiab cov tshauv tsawg yog qhov tseem ceeb rau cov neeg sawv cev carburizing, vim tias cov ntsuas no cuam tshuam ncaj qha rau kev ua haujlwm ntawm carburizing, qhov zoo ntawm casting thiab cov nqi tsim khoom, thiab yog cov txheej txheem tseem ceeb rau kev ntsuam xyuas kev ua tau zoo ntawm cov neeg sawv cev carburizing. Kev tshuaj xyuas tshwj xeeb yog raws li nram no:
1. Cov pa roj carbon ruaj khov siab: Lub hauv paus ntawm cov pa roj carbon ua rau kev ua haujlwm zoo dua
Lub luag haujlwm tseem ceeb: Cov pa roj carbon ruaj khov yog cov khoom siv zoo uas koom nrog kev nce cov pa roj carbon hauv cov khoom ntxiv carbon, thiab nws cov ntsiab lus ncaj qha txiav txim siab qhov cuam tshuam ntawm kev nce cov pa roj carbon. Cov ntsiab lus carbon ruaj khov siab dua, cov khoom ntxiv carbon tuaj yeem muab tau ntau cov ntsiab lus carbon ib chav, thiab qhov ua tau zoo ntawm kev ntxiv carbon ntau dua.
Kev Lag Luam: Cov pa roj carbon ruaj khov siab tuaj yeem txo cov pa roj carbon ntxiv uas siv thiab txo cov nqi tsim khoom. Piv txwv li, yog tias cov pa roj carbon ruaj khov nce ntxiv los ntawm 90% mus rau 95%, qhov ua tau zoo ntawm cov pa roj carbon nce ntxiv tuaj yeem nce ntxiv los ntawm 10% mus rau 15%, thaum txo cov kev cuam tshuam ntawm cov khoom tsis huv xws li tshauv ntawm cov txheej txheem smelting.
Kev sib raug zoo ntawm cov txheej txheem: Hauv kev siv lub tshuab hluav taws xob induction furnace smelting, cov neeg sawv cev carburizing uas muaj cov pa roj carbon ntau tuaj yeem yaj sai dua thiab tawg sib npaug, zam kev hloov pauv hauv kev ua haujlwm casting los ntawm kev nqus cov pa roj carbon tsis sib npaug.
2. Cov tshauv tsawg: Txo cov kev cuam tshuam ntawm cov khoom tsis huv thiab ua kom cov khoom siv smelting zoo dua
Qhov txaus ntshai ntawm cov tshauv: Cov tshauv yog cov khoom tsis muaj carbon hauv cov khoom ntxiv carbon (xws li cov hlau oxides, silicates, thiab lwm yam). Yog tias nws cov ntsiab lus siab dhau, nws yuav tsim ib txheej slag, encapsulating cov pa roj carbon thiab cuam tshuam lawv cov yaj, txo qhov kev nqus carbon. Piv txwv li, thaum cov ntsiab lus tshauv nce ntawm 2% mus rau 5%, qhov kev nqus carbon yuav poob qis 20% mus rau 30%.
Lub nra hnyav ntawm cov txheej txheem: Cov tshauv ntau kuj tseem yuav ua rau cov slag ntau ntxiv, ua rau lub sijhawm ntxuav slag ntev dua, thiab ua rau kev siv hluav taws xob thiab kev siv zog ua haujlwm ntau dua. Hauv lub cub tawg melting groove induction, cov tshauv sib sau ua ke yuav txhaws qhov melting groove thiab txo qhov ua haujlwm hluav taws xob.
Kev Pheej Hmoo Zoo: Cov khoom tsis huv hauv cov tshauv yuav nkag mus rau hauv cov castings, ua rau muaj qhov tsis zoo xws li porosity thiab shrinkage cavities, uas tuaj yeem cuam tshuam rau cov khoom siv kho tshuab thiab qhov zoo ntawm qhov chaw.
3. Tsis muaj sulfur ntau: Tsis txhob cuam tshuam rau spheroidization thiab ua kom muaj kev ua tau zoo ntawm cov hlau cam khwb cia
Qhov txaus ntshai ntawm cov leej faj: Cov leej faj yog ib qho "cuab yeej txaus ntshai" rau cov hlau ductile. Nws tuaj yeem cuam tshuam rau kev ua haujlwm ntawm cov neeg sawv cev spheroidizing (xws li magnesium thiab cov av tsis tshua muaj), ua rau muaj kev cuam tshuam thiab txo qis ntawm cov graphite spheres, thiab txawm tias cov duab ntawm flake graphite, ua rau lub zog thiab kev tawv ntawm cov castings txo qis.
Cov txheej txheem yuav tsum tau ua: Thaum tsim cov hlau ductile, cov ntsiab lus sulfur hauv cov hlau molten thawj yuav tsum tau tswj hwm nruj me ntsis ntawm ≤0.015%. Yog li ntawd, cov ntsiab lus sulfur ntawm cov pa roj carbon additive yuav tsum qis heev (feem ntau ≤0.05%) kom tsis txhob muaj kev pheej hmoo ntawm kev ntxiv sulfur.
Cov kev zam rau cov hlau grey cast: Cov hlau grey cast xav tau qee cov sulfur ntsiab lus (0.06% -0.12%) kom ruaj khov cementite thiab tiv thaiv kev nthuav dav ntawm graphitization. Txawm li cas los xij, cov sulfur ntsiab lus ntawm lub carburizer tseem yuav tsum tau tswj hwm kom tsis txhob muaj cov sulfur ntau dhau ua rau muaj cov hlau dawb cast.
4. Cov pa nitrogen tsawg: Tiv thaiv cov qhov tsis zoo ntawm cov porosity thiab ua kom cov qauv metallographic zoo dua
Qhov sib npaug ntawm nitrogen: Hauv cov hlau grey cast, nitrogen tuaj yeem ruaj khov pearlite thiab khoov thiab passivate graphite, yog li txhim kho cov khoom siv kho tshuab (xws li lub zog tensile thiab hardness). Txawm li cas los xij, thaum cov ntsiab lus nitrogen ntau dua qhov sib npaug ntawm qhov sib npaug (kwv yees li 140ppm), cov castings yuav tsim cov qhov me me zoo li nitrogen, ua rau muaj kev nce ntxiv ntawm cov khoom seem.
Kev tswj cov txheej txheem: Cov ntsiab lus nitrogen ntawm cov carburizer siv rau cov hlau grey cast feem ntau yog tswj ntawm 70-120 PPM, thaum rau cov hlau ductile, uas muaj kev nkag siab ntau dua rau porosity, yuav tsum xaiv cov carburizer nrog cov ntsiab lus nitrogen qis dua (xws li ≤200ppm).
Cov kev cai siv siab heev: Hauv cov khoom siv precision xws li lub cav crankshafts, cov nitrogen ntau dhau yuav ua rau cov khoom siv kho tshuab tsis zoo. Yog li ntawd, cov khoom ntxiv uas muaj nitrogen tsawg yog qhov tseem ceeb heev.
Kev cuam tshuam dav dav: Kev lees paub zoo, zoo thiab pheej yig casting
Kev nce cov pa roj carbon ua haujlwm tau zoo: Cov pa roj carbon ruaj khov siab thiab cov tshauv tsawg ua kom cov pa roj carbon yaj sai thiab nqus tau, txo lub sijhawm smelting.
Cov castings zoo: Cov sulfur tsawg thiab nitrogen tsawg tiv thaiv kev ua tsis tiav ntawm spheroidization thiab porosity defects, ua kom ntseeg tau tias cov khoom siv kho tshuab thiab qhov zoo ntawm qhov chaw.
Kev tswj tus nqi: Los ntawm kev txo cov pa roj carbon uas siv, txo kev siv hluav taws xob thiab tus nqi ntawm cov khoom tsis zoo, tag nrho cov nqi tsim khoom tau txo qis heev.
Kev txheeb xyuas piv txwv
Cov khoom siv ntxiv rau cov pa roj carbon graphite: Cov pa roj carbon ruaj khov ≥99%, cov tshauv muaj ≤0.5%, sulfur ≤0.05%, nitrogen ≤200ppm. Nws tsim nyog rau cov hlau ductile thiab muaj cov txiaj ntsig ntxiv cov pa roj carbon ntau dua 90%.
Cov pa roj carbon ntxiv rau Calcined anthracite: Cov pa roj carbon ruaj khov 90% -95%, tshauv 4% -5%, sulfur 0.3% -0.5%, nitrogen 800-1200ppm. Nws yog qhov tsim nyog rau cov hlau grey cast, tab sis cov tshuaj yuav tsum tau tswj kom tsis txhob muaj cov sulfur thiab nitrogen ntau dhau.
Lub sijhawm tshaj tawm: Lub Yim Hli-25-2025